This disclosure generally relates to an aircraft gearbox. More particularly, this disclosure relates to an aircraft gearbox for high attitude applications. Gears and bearings within a gearbox should not be submerged during operation. Accordingly, a gearbox is typically designed with a lubricant reservoir that maintains lubricant such that gears and bearings are not submerged during operation. In some aircraft applications, the extreme attitudes in which the gearbox is required to operate may result in some of the gears and/or bearings being at least partially submerged in the more extreme orientations. Some aircraft gearboxes for high attitude applications utilize large lubricant reservoirs to provide sufficient space to prevent gears and bearings from becoming submerged even at the more extreme orientations. Alternatively, some aircraft gearboxes utilized for extreme attitudes include lubricant pumps in combination with remote lubricant reservoirs to prevent submersion of gears.